Roth vs Traditional IRA: the income-bracket decision tree

The rule is simple. Pay tax now if you expect to be in a higher bracket later (Roth). Pay tax later if you expect to be in a lower bracket later (Traditional). Everything else is noise dressed up as nuance.

The 2026 IRA contribution limit is $7,500, or $8,600 if you're 50 or older. That's per person, across all your IRAs combined. You can split it across Roth and Traditional however you want. The decision isn't which account exists, it's which dollar of contribution belongs in which bucket.

The fundamental tradeoff

A Traditional IRA gives you a deduction today. You skip federal tax on the contribution, the money grows tax-deferred, and you pay ordinary income tax when you pull it out in retirement. A Roth flips it. You pay tax now on the contribution, the money grows tax-free, and qualified withdrawals come out tax-free after 59 1/2.

If your marginal rate today equals your marginal rate in retirement, the two are mathematically identical. Same dollar in, same dollar out. The decision only matters because the rates almost never match.

Two other things to keep in mind. Traditional IRAs force Required Minimum Distributions starting at age 73 (SECURE Act 2.0). Roth IRAs don't, ever, during the owner's lifetime. That's a real planning lever for anyone who wants to leave money compounding into their 80s, or hand it to heirs.

When Traditional wins

You're in the 24% bracket or higher today and you have a realistic plan to retire with less taxable income than you earn now. Most high-earning W-2 professionals fit this. A married couple with $300,000 of household income is well inside the 24% bracket. If they're maxing two IRAs, that's $15,000 deducted. At 24% federal, that's $3,600 in their pocket this year, before state tax even enters the picture.

Compare that to retirement spending. If the same couple spends $120,000/year in retirement, most of it pulled from pre-tax accounts, they're effectively in the 12% bracket after the standard deduction ($32,200 joint for 2026). The arbitrage is roughly 12 percentage points per dollar. That's the whole game.

Traditional also wins when you're in a high state-income-tax state today and plan to retire somewhere with no state tax. California to Nevada, New York to Florida. The state arbitrage stacks on top of the federal one and can be worth another 5 to 10 points.

When Roth wins

You're in the 10% or 12% bracket today. That's it. That's the whole case. Paying 12% now to avoid paying 22% or 24% later is the highest-conviction trade in personal finance.

Single filers earning under about $48,475 of taxable income (2025) sit in the 12% bracket. Married filing jointly under $96,950. If you're there, max the Roth. Don't think about it. The deduction you'd get from a Traditional contribution is worth almost nothing at that rate, and you're locking in today's historically low brackets for the rest of your life.

Roth also wins in three specific cases regardless of bracket:

• You expect to inherit, sell a business, or have a one-time income event that will push you into a high retirement bracket. Pre-pay the tax on the IRA contributions while you're still cheap.
• You want estate-planning flexibility. No RMDs means the account keeps compounding tax-free past 73, and heirs get a tax-free asset (under the 10-year rule).
• You're young. A 25-year-old in the 22% bracket who lives to 90 has 65 years of tax-free compounding ahead. That's a different calculation than a 55-year-old has, even at the same bracket.

The 22% bracket pivot

Most savers sit somewhere in the 22% bracket. Single filers between roughly $48,475 and $103,350. Joint filers between $96,950 and $206,700. This is where the decision gets actually interesting, and where most online advice gives up and says "do both."

Here's the better framing. The 22% bracket is the historical median for retirees who saved diligently. So if you're in 22% today and you expect to be in 22% later, you're flat. The decision then comes down to second-order factors: future tax-rate risk, state-tax arbitrage, RMD planning, and what other accounts you already have.

2026 marginal bracket	Recommendation	Why
10% / 12%	Roth, full stop	Lowest bracket you'll ever pay. Lock it in.
22% (single, lower half)	Split, lean Roth if young	Tax-rate risk and time-horizon favor pre-paying.
22% (joint, upper half)	Split, lean Traditional if 45+	Less compounding runway, more deduction value.
24%	Traditional, with Roth backdoor	Deduction value high, retirement bracket likely lower.
32% and up	Traditional (or backdoor Roth)	You'll almost certainly retire into a lower bracket.

One more thing on Roth eligibility. The 2025 phase-out for direct Roth contributions starts at $150,000 of MAGI for single filers, $236,000 for married filing jointly. Above $165,000 single or $246,000 joint, direct Roth is closed. The backdoor Roth (non-deductible Traditional contribution converted to Roth) is still legal and widely used, but it requires zero pre-tax balance in any IRA to work cleanly, because of the pro-rata rule.

Where most people get this wrong

Three recurring errors.

Treating the contribution year and the withdrawal year as the same decision. Your bracket today is observable. Your bracket in 30 years is a forecast. Most people make a Roth-vs-Traditional call based on a vibe about future tax rates ("taxes will be higher!") without checking what their own retirement bracket actually looks like at their planned spending. A $4 million Traditional IRA spending $160,000/year is in a different bracket than a $1 million IRA spending $40,000/year. Run the numbers on your spending, not on macro headlines.

Ignoring the deduction's actual value. A Traditional contribution at the 12% bracket saves $900 in federal tax on a $7,500 contribution. The same contribution at 24% saves $1,800. At 32%, $2,400. The deduction is a real number, not a vague benefit. Multiply your bracket by your contribution. If the answer is small, you're probably making the wrong choice by going Traditional.

Forgetting RMDs exist. Required Minimum Distributions hit at 73 and they're computed off the entire pre-tax balance. A couple with $3 million in Traditional IRAs is looking at roughly $113,000 of forced withdrawals in their first RMD year, on top of Social Security and any other income. That can push them from the 22% bracket they planned for into the 24% or 32% bracket they didn't. Roth balances don't have this problem. If you're a high saver, the RMD math itself can flip the right answer toward Roth.

None of this is exotic. It's a marginal-rate trade, with a few wrinkles around eligibility and forced distributions. The mistake is treating it as a personality test (am I a Roth person or a Traditional person?) instead of a bracket comparison. Look at your 2026 marginal rate. Forecast your retirement spending honestly. Pick the lower-tax side.